Corticobasal degeneration: Evaluation of cortical atrophy by means of hemispheric surface display generated with MR images

PURPOSE: To determine the characteristics of cortical atrophy in corticobas al degeneration and Alzheimer disease by using a hemispheric surface displa y generated with magnetic resonance (MR) images. MATERIALS AND METHODS: The magnitude and extent of cortical atrophy were ev aluated with MR hemispheric surface display and volumetric measurement in t hree groups: 17 patients with corticobasal degeneration, 17 matched patient s with Alzheimer disease, and 17 matched healthy control subjects. RESULTS: The extent and magnitude of cortical atrophy were larger in the gr oup with corticobasal degeneration than in the group with Alzheimer disease . The parasagittal and paracentral regions were significantly more atrophic in patients with corticobasal degeneration than in patients with Alzheimer disease (P < .05). The mean hemispheric-to-total intracranial volume ratio s were significantly smaller in the patients with corticobasal degeneration (61%) and those with Alzheimer disease (64%) than in control subjects (69% ). Asymmetry of hemispheric volume was significantly larger in the group wi th corticobasal degeneration than in the control group. CONCLUSION: The extent of cortical atrophy in corticobasal degeneration is more widespread than was previously thought. Parasagittal and paracentral a trophy is a distinctive feature of corticobasal degeneration and distinguis hes it from Alzheimer disease.